RandomUtil.java

/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.classic.corpus;

import java.util.Random;

public class RandomUtil {

    /**
     * Approximate a gaussian distrib with only positive integer values
     * 
     * @param average
     * @param stdDeviation
     * @return
     */
    static public int gaussianAsPositiveInt(Random random, int average, int stdDeviation) {
        if (average < 1) {
            throw new IllegalArgumentException("The average must not be smaller than 1.");
        }

        if (stdDeviation < 1) {
            throw new IllegalArgumentException("The stdDeviation must not be smaller than 1.");
        }

        double d = random.nextGaussian() * stdDeviation + average;
        int result = 1;
        if (d > 1.0) {
            result = (int) Math.round(d);
        }
        return result;
    }
}